package com.dslu.fx.utils;

import java.util.AbstractList;
import java.util.List;

/**
 * List拆分多个list
 * @author DuanLinpeng
 * @date 2021/01/08 19:15
 **/
public class ListSplitUtils {

    public static <T> List<List<T>> partition(final List<T> list, final int size) {
        if (list == null) {
            throw new NullPointerException("List must not be null");
        }
        if (size <= 0) {
            throw new IllegalArgumentException("Size must be greater than 0");
        }
        return new Partition<>(list, size);
    }

    private static class Partition<T> extends AbstractList<List<T>> {
        private final List<T> list;
        private final int size;

        private Partition(final List<T> list, final int size) {
            this.list = list;
            this.size = size;
        }

        @Override
        public List<T> get(final int index) {
            final int listSize = size();
            if (index < 0) {
                throw new IndexOutOfBoundsException("Index " + index + " must not be negative");
            }
            if (index >= listSize) {
                throw new IndexOutOfBoundsException("Index " + index + " must be less than size " +
                        listSize);
            }
            final int start = index * size;
            final int end = Math.min(start + size, list.size());
            return list.subList(start, end);
        }

        @Override
        public int size() {
            return (int) Math.ceil((double) list.size() / (double) size);
        }

        @Override
        public boolean isEmpty() {
            return list.isEmpty();
        }
    }

    public static void main(String[] args) {
       /* List<String> list = new ArrayList<String>();
        for (int i=0; i<88;i++){
            list.add(i+"");
        }
        List<List<String>> partition = ListSplitUtils.partition(list, 100);
        for (int i=0; i<partition.size();i++){
            System.out.println("i=" +(i+1)+"组 >>>"+ partition.get(i).size());
        }*/
        double i = 7 / 3.0;
        System.out.println(Math.ceil(i));
    }

}

